Acetylation of monochlorhydrocarbons.



F UNITED sTArEs ATENT OFFICE.

WALTER E. MASLANLD, or w ILMINeroN, D LAWARE, ASSIGNOR r E. I. DU roNrDE NEMOURS rownnn COMPANY. or WILMINGTON, DELAWARE, A CORPORATION or NEWJERSEY.

1,077,988. No Drawing;

To all-whom may concern Be itknown. that I, WALTER E. MASLAND, ofWilmington, in the county of Newcastle, and in the State of Delaware,have invented a certainnew and useful Improvement in the Acetylation ofMonochlorhydrooarbons, and dohereby declare that they following 1s afull, clear, and exact description thereof.

My invention relates particulanly to the acetylation ofmonochlorhydrocarbons, and especially monochlorh-ydrocarbons derivedfnomhydrocarbonsof the paraifin series. It. is, however, applicable tothe acetylatlon of many other organic compounds.

the acetylation of compounds of the above character, and especiallythose derived from certain members of the parafiin series ofhydrocarbons, in an advantageous manner.

My invention is particularly applicable to obtaining pentyl and hexylacetates, as well,

as certain unsaturated hydrocarbons which are formed in the reaction. D

The surprising fact, which-is a basis of the present application, isthat by using acetic acid of from 70 to 99 per cent. sub

stantially the same yields can beobtained as with the use of glacialacetic acid.

As one illustrative embodiment of my 1n-' vention, I will describe theacetylation of monochlorhydrocarbons derived from pentane and hexane andtheir isomer-ids. As

1 suming that pentane, isopentane, hexane and isohexanes have beenobtained by fractionation of a mixture of hydrocarbons such, for

lexampleyas ga'solene, and that they have been subjected to chlorinationby treatment with chlorin in the presence of light to producemonochlorhydrocarbons, and that the products thus obtained are distilledto separate the monochlorhydrocarbons from the remaining products, thesemonochlorhydrocarbons are subjectedto acetylation in the followingmanner: The monochlorhydrocarbons are placed ina vessel tightly sealedand capable of withstanding a high pressure, together with a quantity ofacetic acid and sodium acetate, sufficient of the latter being providedto. combine with all the chlorin present. The amount of acetic acidwould vary with the nature of the substance treated, but in general itmay be stated that an amount is added equal in weight to themonochlorhydrocarbons; I have discovered that the reaction can beeii'ected by the use of Acn'rYitArIo' or MONQQHLORHYDROCARBQNS.

{sodium acetate. I have also discovered that {the acetic'acid used maybe of any concenftration. down to 70%, while the literature states thatglacial acetic acid e. stronger ;than'99%);-must be'used. The vessel isthen heated, preferably by a steam jacket, with fsteam at the ordinaryworking pressure of about 1.0.0 pounds, and then with superheated steam,or steamat. approximately250 pounds pressure, to raise the temperatureto about 180C. or above. The charge should preferably .be heated fromtwoto twelve hours, ac- ,cording to the temperature used; the higher thetemperature, the shorter the time re- The object of my invention is tobring about quired. The reaction having been completed, the contents ofthe vessel are distilled either still are finally subjected todistillation by and oily products are distilled over and separated fromeach other. The acid thus obtained is concentrated by rectification, andin the process of rectification a small. quantity of soluble, oilyvmaterial is obtained in the first distillate. The oily products ofacetylation are then treated to neutralize the same by the addition ofsodium carbonate or other alkali. The neutral product thus obtainedisusedwithout separation, or it is redistilled to separate it into itsvarious component parts and remove impurities. The purified product willthen contain mon'oacetic esters together with certain unsaturatedhydrocarbons of the olefin series, having the same number of carbonatoms as the original chlorhydrocarbons, due to decomposition of some ofthe chlorhydrocarbons. A molecule of acetic acid will also be producedin the process of acetylation for each molecule of olefin. The desiredreaction which takes place is as follows, while some secondary reactionsmay also occur:

Amyl acetate. Sodium chlorid. chlorid.

When the process is carried out in accordance with my invention it canbe effected I acetate" c p p1+N gcgocu c n coocn Naol my 0 mm much morecheaply than in the manner in 1 great savlng in expense of acid andapparabefore or after cooling. The contents of the tus. Where aceticacid of low concentration is used, the acid does' not attack the wallsof the vessel to as great an extent as in the case of the use of aceticacid of higher concentrations.

While I have described my invention above in detail I wish itto beunderstood that many changes may be mad'e therein without departing fromthe spirit of my invention.

I claim: v

1. The'process which comprises acety1at ing a halogen derivative ofhydrocarbon by an acetate and acetic acid of from 70% to 99% strength.

2. The process which comprises acetyiating a chlorhydrocarbon by anacetate and acetic acid of from 70% to 99% strength.

3. The process which comprises acetylatin a chlorpentane by an acetateand acetic acid of from 70% to 99% strength.

4. The process which comprises acetylatin a halogen derivative ofhydrocarbon by sodium acetate and acetic acid of from 70% to 99%strength. I

5. The process which comprises acetylating a chlorhydrocarbon byscdiu'macetate and acetic acid of from 70% to 99% strength.

6. The process which comprises acetylating a chlorpentane by sodiumacetate and acetic acid of from 70% to 99% strength.

7. The process which comprises acetyiating a mixture of a chiorpentaneand a chlorhexane by sodium acetate and acetic acid of from 70% to 99%strength.

In testimony that I claim the foregoing I have hereunto set my hand.

I WALTER E. MASLAND. Witnesses:

C. R. Muncn, A. M. GORMAN.

